Oracle String Tokenizer

select
get_token('foo,bar,baz',1), -- 'foo'
get_token('foo,bar,baz',3), -- 'baz'

get_token('a,,b',2), -- '' (null)
get_token('a,,b',3), -- 'b'
get_token('a|b|c',2,'|'), -- 'b'
get_token('a|b|c',4,'|') -- '' (null)
from
dual